The invention relates to a regulating device, and in particular to a device for regulating the proportions of the operating mixture of an internal combustion engine. The regulating device is part of a fuel metering device with a fuel supply line having a throttle member arranged therein. The throttle member can be activated, in accordance with the air flow drawn into the induction tube, by means of an air flow rate meter of the internal combustion engine. The throttle member has a metering cross section, and downstream of the metering cross section lies an uncontrolled pressure chamber of a differential pressure valve. The differential pressure valve also has a controlled pressure chamber lying upstream of the metering cross section. A pressure relief line provided with a throttled end leads from the controlled pressure chamber. The pressure relief line is connected with the operating chamber of a servo-motor upstream from the throttle, which servo-motor is connected with a throttle plate arranged in the induction tube downstream of the air flow rate meter.
This type of regulating device has the disadvantage, however, in that during very rapid adjustment movements of the fuel rate adjusting member of the fuel metering device the following regulating process by the differential pressure valve, and the thus controlled servo-motor for adjustment of the throttle plate, cannot be completed fast enough, so that there is a temporary over-enrichment of the operating mixture and a surge of exhaust smoke during acceleration. This is especially true when the fuel supply pump has only a limited supply performance capability, so that the necessary fuel rate for the adjustment of the servo-motor is not available soon enough.